For excitations consisting of a continuum of plane-waves [1]}, with propagation directions covering the unit sphere, the scattered far field is similarly given by
\(F̭({r}) = J\dfrac{4\pi }{k} \int \limits _{4\pi } S̭({r},{r}^{\prime }) \cdot Ḙ_0 ({r}^{\prime }) ,\) 
